A comparison of ac traction and dc traction locomotives

a comparison of ac traction and dc traction locomotives Often, people ask about the differences between ac and dc motors as used in locomotives and multiple-units in the early days of electric traction at the beginning of this century both types were tried the limits of the technology at the time favoured the dc motor it provided the right torque characteristic for railway operation.

Regenerative braking and advanced wheel slip/spin control comparison of ac- 77 ac torque motor to d77 dc motor (62:15 gear ratio with 40” wheels) ac-77 ac torque motor for locomotives 11,000nm ac torque motor alternative to existing d77 dc motors for locomotives ac-77 peak d77 peak ac-77 continuous. Electric locomotives are also usually quieter, more powerful, and more responsive and reliable than diesels they have no local emissions, an important advantage in tunnels and urban areas some electric traction systems provide regenerative braking that turns the train's kinetic energy back into electricity and returns it to. A3 dc and ac traction motors rj hill consultant engineer, france abstract this paper describes the use of electrical machines as the prime mover in railway locomotives and vehicles first, the loading of traction machines is examined from knowledge of vehicle movement dynamics within the traction duty cycle. Skf has ac and dc traction motor test solutions that completely evaluate the condition of test results are compared to preset, user-defined test limits to the skf static motor analyzer – baker awa-iv is used for testing ac traction motors in locomotives in maintenance and repair depots at leading railway companies. Locomotives and electric trains based on dc-dc ac-ac systems [2] proved unreliability of traction engine as part of the electric drive most failures of a dc the difference f ff ∆= − 2 1 is referred to as absolute rotational speed of the rotor the frequency of em induced by the rotating rotor is the same according to the.

a comparison of ac traction and dc traction locomotives Often, people ask about the differences between ac and dc motors as used in locomotives and multiple-units in the early days of electric traction at the beginning of this century both types were tried the limits of the technology at the time favoured the dc motor it provided the right torque characteristic for railway operation.

There is described the influence of mechanical characteristics of ac traction motors to the formation of wheel slip process and there are provided keywords: diesel-electric locomotives, ac traction motor, slip-slide control system, adhesion coef- ficient, traction significantly more reliable and unsophisticated if compared. With the development of on-board ignitron, excitron tube and later solid state rectifier, ac arrived at the scene as the feeding voltage transfer of power at 25kv single phase to locomotive and then converting it into dc for traction motor was demonstrated by sncf and indian railways also decided to follow. Keywords: dynamic braking, traction motors, wheel/rail adhesion, train braking distance longitudinal train distance will allow trains to be spaced closer together, with reasonable confidence that they will the goal of both control systems for dc and ac traction motors is to apply maximum available. Performance analysis and comparisons of those drives as follows: χ the maximum attainable factor of adhesion by ac traction motors is 35 to 45 percent while dc motors are limited to 30 percent for a given horsepower rating therefore, a 4000 hp ac locomotive has the same tractive effort capacity as a 5000 hp dc.

Grid sub-station locomotive step down transformer ac-dc converter dc series motor 3-phase 50 hz 33 kv to 132 kv line traction sub-station 50 hz 25 kv 1-phase figure 75 single phase ac to dc system 716 comparison of dc and ac system of railway electrification from the point of view of main line and. According to present scenario the one of the most efficient transportation system is traction system in the history of railway first railway locomotive was designed by john blenkinshop in 1811 and it was a steam locomotive after that in the year 1838 many experiment were started on electric railway and in 1881 for first time.

Apart from maglevs (magnetically levitating trains), a simple electric traction train uses dc series motor (rated 1500v dc in india) which is supplied through ac dc traction motors have greater maintainence cost compared to ac motors as brushes emit carbon dioxide due oxidation due to operation for long time while ac. Electric locomotive systems are predominant traction systems compared to diesel and steam locomotives track electrification includes both ac and dc systems. Development of high power and high speed locomotives and trains at present, high speed electric vehicles mostly work with three-phase induction motors or three-phase synchronous motors as traction motors the two electric machine types have different efficiencies at different operation points, and experience differences. The advent of modern power electronics and ac asynchronous traction motors has considerably reduced the volume of traction equipment this (along with other technological developments) has facilitated the development of trains with decentralized traction, so-called electric multiple units (emus) a similar development.

In three-phase squirrel-cage ac traction motor, alternative aluminium alloy rotor bars have been proposed and design established in view of achieving better performance for entire locomotive locomotives, dc series traction motors were used been compared and co-related with actual targets so that. The dc supply is then applied to the dc motor via suitable contact system and additional circuitry dc traction system the advantages of this system include in case of heavy trains that require frequent and rapid accelerations, dc traction motors are better choice as compared ac motors dc train. Slip it keeps comparing the wheel speed with land speed with the help of a radar • this permits full exploitation of adhesion to be applied in traction available on any other electric or diesel locomotive in india • higher safety due to better dynamic brakes nearly 50 % higher braking power as compared to conventional. Comparison of dc and ac traction machines 2 system aspects and general requirements for traction converters 3 state of the art igbt-technology, an overview 4 the traction converter family sibac® ➢ modular building blocks ➢ sitrac® improved traction control system ➢ railway vehicles with igbt-traction.

A comparison of ac traction and dc traction locomotives

While it has been used in locomotives for over two decades (especially in europe ), it has only been recently that the price of the drives has allowed them to be used in most of the new diesel-electric locomotives in the united states the ac drive works by converting the traction alternator output to dc (direct current) and. Loop current control for the four quadrants ac-dc converter used in high-speed traction locomotive with ac traction line the paper shows two different structures for the converter and makes a comparison between their performances, underlining that a conversion structure composed by two series connected converters. Diesel locomotives never reached the speeds of electric locomotives however, the latter require a greater investment in infrastructure to electrify the line as we all know, it is electric locomotives that are at the forefront of railway traction, while the diesel locomotive is kept for some very specific uses.

Electric traction systems the system which use electrical power for traction system ie for railways, trams, trolleys, etc is called electrical traction the track electrification refers to the type of source supply system that is used while powering the electric locomotive systems it can be ac or dc or a composite supply. ➃ the characteristics of ac drive compared with dc drive ➄ the key technologies of ac traction drives ➅ the development 9 electric railway traction ac drive systems the experimental records of heavy-load freight trains in the world the experimental records of heavy-load freight trains in the world.

System can recovered by using a regenerative braking system a new model of inverting substation for dc traction systems show in fig 1 is proposed to absorb the regenerative power in the dc line that cause by the electric brakes there are two different types of locomotive rail lines, ac and dc which the regeneration. Merits of ac vs dc locomotives 1 the merits of ac vs dc locomotives november 13, 2008 contains proprietary electro-motive information that shall not be disclosed to third parties 1 2 the merits of ac vs dc tractiom 1 emd historical perspective 2 development of ac traction 3 performance and. Electric freight locomotive to date the powerhaul series also represents an an advanced ac traction system and dynamic braking fuel efficient driven by the rugged powerhaul series p616 engine, the locomotive reduces fuel use by up to 5% compared to current operating fleet averages not only will this fuel. This page shows the internal arrangement for a typical ac electric locomotive and offers a selection of terms used in electric traction if you can't find it here, try our modern the difference is that contactors normally latch or lock closed and have to be opened by a separate action a lighting contactor will have two, low.

a comparison of ac traction and dc traction locomotives Often, people ask about the differences between ac and dc motors as used in locomotives and multiple-units in the early days of electric traction at the beginning of this century both types were tried the limits of the technology at the time favoured the dc motor it provided the right torque characteristic for railway operation.
A comparison of ac traction and dc traction locomotives
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